The data dump does not appear to have story points, which are part of the Sprint Extension. I checked this by looking at a task in Phab with a Story point total (97069) and then inspecting the JSON for it. I suspect that this may be resolvable without diving into any Sprint Extension schema, but instead by adding story points to the list of safe transaction types (found here:
transactions = ['projectcolumn', 'priority', 'status', 'reassign']
) but I'm not 100% sure, and not sure that what the transactiontype for sprint points is called exactly.